Improvement in mainspring attachments



vL-C. EDWARDS.

Main-Spring Attachments.

No.15l,765, y Patentedjune 97,1874.

WITNESSES: v INV TUR: PM( ma@ VQ/ND B ATTRNEYS.

UNITED STATES JAMES C. EDVARDS, OF BINGHAMTON, NEW7 YORK.

IMPROVEMENT IN MAINSPRING ATTACHMENTS.

Specification forming part of Lettels Patent No 151,765, dated June 9,1874; application tiled March 7, 1874.

To all whom fit may concern:

Be it known that I, JAMES C. EDWARDS, of Binghamton, in the county ofBroome and State of New York, have invented a new and ImprovedMainspring and Barrel-Arbor Gonneetion, ot' which the following is aspecitieation:

My invention consists of' an eccentric notch or recess in the face ofthearbor of the barrel to which the mainspring` of a watch is connected,the notch beingI as deep as the thickness ofthe spring, and terminating'with the end of the spring by a radial wall, extending to the truecircumference ot' the arbor.

The object is to so shape the arbor that the spring end will not form anabrupt projection for the first coil of the spring to wind over, whichproduces an extra strain and bend at that point, and weakens it so thatit breaks, moreover, causing an irregular action of the watch, which itis desirable to avoid.

The drawing is a plan view of the barrel and mainspring, showing myimprovements.

A represents the hub or collar ofthe arbor of the barrel; B, themainspring, and C the eccentric notch in the face of the collar, inwhich the end of the spring is fastened, so that its outer side is Hushwith the circumference ot the collar at the end of the notch, and fromthe end ofthe eccentric curve of the bottom ofthe notch is so gradualthat the injurious effects produced by connecting` the spring on ktheface of the hub without a notch are Wholly

